Finding the Fourth Proportional to 8,111.62, 12,168.68 and 3,431.64

Step by Step Solution

1. Step 1: Write the proportion equation
   8,111.62 : 12,168.68 = 3,431.64 : x
2. Step 2: Convert to fraction form
   8,111.62/12,168.68 = 3,431.64/x
3. Step 3: Cross multiply
   8,111.62x = 12,168.68 × 3,431.64
4. Step 4: Simplify right side
   8,111.62x = 41,758,529.04
5. Step 5: Solve for x
   x = 41,758,529.04/8,111.62
6. Step 6: Final answer
   x = 5,147.99